My battery went from "hmm, wonder if something is up?" to "holy chit what is wrong?", all in less than a week. Truck would stop running pulling away from a light. Other times the radio would shut off and clear all presets. Lights on dash. Took a look and the thing was four years old...

Big Truck: 00, 3.5, Endeavor, 5-Spd drive line in hand!
Little Truck: 87, 2.6T I/C, MT, LSDs, Tonneau Top
Her Truck: 03, 3.8, 20th Anniv, 65k
Daughter's: 06 Eclipse, Keeping it Mitsu!
FSMs: MitsubishiLinks.com